Optical transmitters that utilize semiconductor lasers have become more important in recent years. One particularly significant application of these types of transmitters is in communication systems where fiber optic communication media is employed. With the growth in electronic communication, communication speed has become more important in order to increase data bandwidth in electronic communication systems. Improved transmitters can play a vital roll in increasing data bandwidth in communication systems using fiber optic communication media such as local area networks (LANs), metropolitan area networks (MANs) and wide area networks (WANs)(e.g. the Internet). A preferred component for optical interconnection of electronic components and systems via optical fibers is a transmitter that utilizes a semiconductor laser.
For example, with reference to FIG. 1, a very basic example of a communication system 100 is shown. In the communication system 100, a first printed circuit board PCB-X 102 of a first host system 103 is optically or communicatively connected to a second PCB-Y 110 of a second host system 111. Particularly, a transmitter-X 104 of PCB-X 102 is connected through fiber optic cable 122 to a receiver-Y 112 of PCB-Y 110 and a transmitter-Y 114 of PCB-Y 110 is connected through fiber optic cable 120 to a receiver-X 106 of PCB-X 102. Accordingly, transmitter-X 104 of PCB-X 102 can transmit photons or light signals (e.g. data) through fiber optic cable 122, which is then received by receiver-Y 112 of PCB-Y 110 where it can be processed by the second host system 111. On the other hand, transmitter-Y 114 of PCB-Y 110 can transmit photons or light signals (e.g. data) through fiber optic cable 120, which is then received by receiver-X 106 of PCB-X 102 where it can be processed by the first host system 103. Thus, a communication system 100 utilizing photons or light signals to communicate data through fiber optic cables between a first and second host system is formed.
One of the major obstacles to the practical implementation of optical communication systems is in the difficulty of achieving sufficiently accurate alignment in and of the various system and subsystem components of the optical communication system, and in maintaining that alignment for extended period of times. This is particularly true for the internal components of optical transmitters (e.g. a semiconductor laser, associated lenses, and other required components), which need to have accurate and sustained alignment for their entire operational life.
Moreover, another obstacle to the practical implementation of optical communication systems is that they must often operate in dirty and/or harsh environments—e.g. where particulates such as dust and liquids (e.g. water) are present. This is particularly true for the components of a transmitter where the continued cleanliness of the components, such as the lenses for the focusing of the light signals, is critical for the continued reliable operation of the transmitter. Further, it is desirable that a transmitter be hermetically sealed to prevent liquids and particulates (e.g. dust) from entering the transmitter and interfering with the operation of the internal components of the transmitter.
Like reference numbers and designations in the drawings indicate like elements providing similar functionality.